• 대한치과보철학회지
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• 제37권5호
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• pp.620-639
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• 1999

Indirect composite resins are used as an popular effective esthetic material in prosthetic dentistry, often with metallic substructure that provides support for restorations. Recently, new indirect composite resins as a substitute of ceramic have been developed. These resins provide good esthetics, with a wide range of hue and chroma. And the flexural strength of those is in the range of 120-150MPa, Which is higher than that of feldspathic Ceramic, and similar th that of Dicor. Although it has many merits, one of the major clinical problems of composite resins is the bond failure between metal and resin due to insufficient interfacial bond strength. The purpose of this study was to evaluate shear bond strength of the reinforced indirect composite resin to dental alloys. Three different composite resin systems($Artglass^{(R)},\;Sculpture^{(R)},\;Targis^{(R)}$) as test groups and ceramic($VMK\;68^{(R)}$) as control group were bonded to Ni-Cr-Be alloy($Rexillium\;III^{(R)}$) and gold alloy(Deva 4). All specimens were stored at $^37{\circ}C$ distilled water for 24 hours and the half of specimens were thermocycled 2000 times at temperature from $5^{\circ}C\;to\;60^{\circ}C$. The shear bond strengths of reinforced indirect composite resins to dental alloys were measured by using the universal testing machine, and modes of debonding were observed by stereoscope and scanning electron microscope. The results were as follows: 1 The shear bond strengths of reinforced indirect composite resins to dental alloys were approximately half those of ceramic to dental alloys(P<0.01). 2. There was no significant difference between the shear bond strength of several reinforced indirect composite resins to metal. 3. Alloy type did not affect on the shear bond strengths of resin to metal, but the shear bond strengths of ceramic to gold alloys were higher than those of ceramic to Ni-Cr alloys(P<0.05). 4. The shear bond strengths of Artglass and Targil to gold alloys were significantly decreased after thermocycling treatment(P<0.01). 5. Sculpture showed cohesive, adhesive, and mixed failure modes, but Artglass and Targis showed adhesive or mixed failures. And ceramic showed cohesive and mixed failures.

• 대한본초학회지
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• 제22권1호
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• pp.71-79
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• 2007

Objectives : This study was designed to establish a characteristic discrimination of internal and external morphological standard of original plants and herbal states in Polygoni Multiflori and Cynanchi Wilfordii Radix. Methods : In this studies, the external-internal morphological standards were determined by using stereoscope and butanol series. Results: 1. The external characteristics of original plants: Polygonum Multiflorum has alternate leaves, and its flower with white color blooms at the shoot apex or leaf axil. In the other hand, Cynanchum wilfordii has opposite leaves, and its flower with yellowish green color blooms at the leaf axil. 2. The physical characteristics of herbal slates: Polygoni Multiflori Radix is red-brown in outer surface pink-brown in section. In the other hand, Cynanchi Wilfordii Radix is earthly-brown in outer surface greyish white in section. 3. The physical characteristics according to the place of production: Demonstrable difference according to the place of production is not seen. Polygoni Multiflori Radix is brown or dark brown in outer surface, soft $Yellow{\sim}dark$ brown in section. In the other hand, Cynanchi Wilfordii Radix is white in outer surface, $white{\sim}weak$ red in section, and has power type. 4. The internal characteristics: Polygonum multiflorum has hetero-vascular bundle and lignification of cork layer is progressive. In the other hand, Cynanchum wilfordii has not hetero-vascular bundle, and lignification of cork layer is weak. Conclusion: In the future, many fundamental study such as how to discriminate between Polygoni Multiflori Radix and Cynanchi Wilfordii Radix in origin and efficacy will be necessary. Also the standard of discrimination must be specific and distinct in that several kinds of fo-ti has been traded. It is considered the results of this study will be furnish κ I the basis Lo succeeding studies and it is needed to extensive comparative study for the same genus-degree of relatedness.

• 대한소아치과학회지
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• 제35권2호
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• pp.195-204
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• 2008

치아 우식증과 침식증의 진단과 본 연구는 교정용 밴드 사용의 대안으로 제시된 직접 부착 술식이 보철 치료를 받은 치아상에서도 적절한 결합 강도를 갖으면서 임상적으로 유용하게 사용될 수 있는지를 평가하고, 불산과 포세린 전처리제의 사용 여부에 따른 결합 강도와 접착 파절 양상의 차이에 대해 알아보고자 시행하였다. 사람의 상하악 소구치 치관 20개를 대조군으로, 소구치의 협면을 복제한 포세린 치관 80개를 실험군으로 나눈 후, 대조군은 37% 인산으로 산부식한 후 Transbond $XT^{(R)}$를 이용하여 금속 브라켓을 접착하였고, 실험군들은 모두 포세린 치관에 통상적으로 sandblasting 처리를 하되, 9.6% 불산으로 4분간 부식처리를 함께 한 군, 포세린 전처리제를 적용한 군, 마지막으로 sandblasting과 불산 그리고 포세린 전처리제를 모두 적용한 군으로 20개씩 나눈 후 금속 브라켓을 접착하였다. 각 군간 전단 결합 강도와 접착 파절 양상을 비교하여 관찰한 결과, 포세린 치관에 금속 브라켓을 접착할 시, 기존의 비심미적인 밴드를 사용하지 않더라도 sandblasting과 불산 그리고 포세린 전처리제를 이용한 직접 부착 술식으로 임상적으로 유용하게 사용될 수 있음을 알 수 있었다.

• 대한치과교정학회지
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• 제28권6호
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• pp.947-954
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• 1998

본 연구는 각각 다른 농도의 황산리튬을 함유한 폴리아크릴산을 적용시간을 변화시켜 치아의 법랑질 표면에 도포하여 크리스탈을 형성하고 그 위에 도제브라켓을 부착한후 전단결합강도와 파절양상을 비교하기 위하여 시행하였다. 농도가 서로다른 흔합용액 4종류를 교정치료를 위해 발거된 건전한 소구치 48개의 법랑질 표면에 적용시켰다. 실험용액들은 $50\%$의 폴리아크릴산과 $65\%$의 폴리아크릴산을 기본 용액으로 하여 0.3M의 황산을 공통으로 첨가하고 각각 0.3M 이나 0.6M의 황산리튬을 첨가하여 만들었다. 30초나 60초 동안 준비된 용액을 법랑질 표면에 적용한 후 브라켓을 부착시켜 전단결합강도를 측정하였다. 또한 브라켓 부착 전과 부착 후의 크리스탈 형성 양상을 주사전자현미경을 통하여 관찰하였다. 치아 표면의 잔여 레진 양을 입체현미경을 통하여 관찰하고 분류하여 다음과 같은 결과를 얻었다. 1. $50\%$ 폴리아크릴산으로 처리하였을 때의 전단결합강도가 $65\%$ 폴리아크릴산에 비해 높았다. 2. 황산리튬의 농도나 적용시간에 따른 전단결합강도의 차이는 인정되지 않았다. 3. 브라켓 제거 후 법랑질 표면에서 레진이 거의 관찰되지 않았다. 4. $50\%$ 폴리아크릴산으로 처리하였을 때의 크리스탈 형성 밀도가 $65\%$ 폴리아크릴산의 경우 보다 높았다.

• 대한본초학회지
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• 제23권4호
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• pp.21-29
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• 2008

Objectives: To determine the standards for discrimination of Magnoliae Cortex, the experiment of specific external-internal characters and the physicochemical pattern analysis were performed. Methods: External characteristics was observed using a stereoscope. Paraffin-mediated sectioned materials were stained by Ju's method. Physicochemical patterns of materials were analyzed using HPLC. Results: 1. Botanical characteristics: Magnolia officinalis had one seed and a white flower, while M. obovata had two seeds and a white flower. Machilus thunbergii had berry and spherical fruits and yellowish green panicles. 2. External characteristics: M. officinalis and M obovata were dark and thick. M. officinalis was gray brown and greasy while M. obovata was light-gray, less oily and smoothly sectioned. Machilus thunbergii was thin and relatively light or yellow-brown, coarsely sectioned and faintly specific scents. 3. Internal characteristics: The bast parts of M. officinalis and M. obovata were commonly wider than Machilus thunbergii The cork cortex of M. officinalis was $10{\sim}mg/L$ cell layers with many oil cells, while that of M. obovata was $4{\sim}7$ cell layers with less oil cells. Machilus thunbergii's xylem which consisted of ring-shaped cambium at 1st and 2nd part was occupied in large portion. 4. Physicochemical pattern: Both M. officinalis and M. obovata involved honokiol and magnolol. All kinds of M. officinalis involved Magnatriol B but one kind of M. ovobata and all of Machilus thunbergii didn't. Machilus thunbergii showed different pattern of chromatogram from that of 2 species above. Conclusions: These results could be used as standards for discrimination of Magnoliae Cortex and as the method of objectification in medicinal herbs giving the basic resource for bioactivity research.

• Restorative Dentistry and Endodontics
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• 제27권5호
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• pp.502-514
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• 2002

The aim of this study was to evaluate the marginal adaptation of direct class II sandwich restoration with packable composites(P-60), resin modified glass ionomer cement(Fuji-II LC), flowable compomer(Dyract Flow), flowable composites(Filtek Flow) in comparison with total bond restorations. In addition, for sandwich restorations, influence of different sandwich techniques was also evaluated. Large butt-joint box typed class II cavites with cervical margins 1mm below the cemento-enamel junction were cut into 70 extracted human molars. The cavities(7 groups, n=10) were filled using a closed/open sandwich restoration or total bond restoration technique with materials according to the manufacturer's recommandation using the single-component bonding agent for each system. Teeth were thermocycled 500 times between 5$^{\circ}C$ and 55$^{\circ}C$ with 30-second dwell time. The teeth were then coated with nail polish 1mm short of the restoration, placed in a 2% methylene blue for 24 hours, and sectioned with diamond wheel. Sections were examined with a stereoscope to determine the extent of microleakage. Dentine /Cementum margins were analyzed for microleakage on scale of 0(no leakage) to 4(entire axial wall) and interface between materials, on scale of 0(no leakage) to 3(axial wall). Results were evaluated with Kruskal Wallis Test, corrected for ties, to determine whether there were statistically significant differences among the seven groups. Pairs of groups were analyzed using the Student-Newman-Keuls Method and Dunn s Method. The results were as follows : 1. All groups showed some micoleakage in cervical portion. But there were no microleakage in interface between materials. 2. Closed sandwich restorations with Fuji-II LC and Filtek Flow had significantly lower leakage rating than total restorations with only P-60. However, open sandwich restorations with Dyract Flow showed significantly higher (P<0.05) 3. Closed sandwich restorations had significantly lower leakage rating than total restorations. However open sandwich restoration s showed significantly higher (P<0.05). 4. Sandwich restorations with Fuji-II LC were iou$.$or leakage than only P-60. Filtek Flow, Dyract Flow. But there were no statistically differences among the materials. From the results above, it could be concluded, closed sandwich restorations was effective in reducing microleakage of class II restorations. The best results showing the least microleakage were for the closed sandwich technique with Fuji-II LC and Filtek Flow.

• 대한치과보철학회지
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• 제35권4호
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• pp.647-661
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• 1997

The resin modified glass ionomer cements(RMGICs) have been used for years since 1989. Recently it has been developed for luting of fixed restorations. To evaluate the bond strength and marginal leakage of RMGICs for luting usage, the 80 extracted human molars which had uniform area of exposed dentin were cemented with 3 types of RMGICs(Fuji Duet, Advance, Vitremer), a conventional Glass Ionomer Cement(GIC-Fuji I), and a resin cement (Panavia 21) to base metal alloy(Ni-Cr-Be). After thermocycling the specimens were immersed in basic fuschin dye for measuring marginal leakage. The shear bond strength was measured with Instron and the maximum dye penetration was measured to 0.1mm. The types of fractured patterns were determined with stereoscope(${\times}7.5$). The results are as follows. 1. The difference between 3 RMGICs and a conventional GIC in shear bond strength was not statistically significant. It seemed that RMGICs had lower shear bond strength than resin cement. (p<0.01) 2. The mean scores of marginal leakage had no significant difference between the resin cement and 3 RMGICs but it was much higher in conventional GIC than the RMGICs (p<0.05) 3. It was determined that the manufacturer and the methods of dentin pretreatment determined the pattern of fracture surfaces and the frequency of adhesive failure between teeth and 3 RMGICs standed as in following order - Vitremer, Advance, Fuji Duet. (p<0. 01) When the fracture pattern was analyzed, it could be said that the materials and the method of dentin pretreatment have much effect on bonding states. This means that the dentin bonding agents should be improved. But the limited products in this experiment can not evaluate the physical properties of the entire RMGICs. Therefore a further study which can evaluate various RMGICs should be in progress to develope better cements.

• Applied Microscopy
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• 제42권1호
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• pp.35-42
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• 2012

피부는 인체에서 가장 큰 조직으로 가장 바깥쪽에 존재하며 다양한 기능을 수행한다. 항상성 유지를 위한 체온조절, 외부 이물질 등에 대한 보호작용, 그리고 촉각이나 통각 및 온도를 느끼는 역할을 수행한다. 이러한 피부는 손톱, 발톱, 털, 땀샘 등의 다양한 부속기관을 가지고 있으며 나이, 성별, 생활환경 등에 의해 다양한 특징을 보이게 된다. 특히 손발의 주름과 같은 미세지형은 피부의 부위에 따라 다양한 형태를 지니며 성별에 따른 차이도 보이는 것으로 알려져 있다. 그러나 한국인 건강한 청년의 피부미세지형에 관한 연구는 아직 진행되지 않았다. 따라서 본 연구에서는 한국인 청년을 대상으로 아래팔 앞쪽, 손등 그리고 가운데 손가락 첫째 마디 등쪽의 피부미세지형을 분석하고 성별 및 위치에 따른 차이를 분석하고자 한다. 실리콘을 이용하여 측정하고자 하는 피부 위치의 모사판을 획득하였으며 획득된 시료는 주름의 빈도, 폭, 깊이 등을 측정하기 위하여 얇게 세절하여 실체현미경으로 촬영 하였으며 성별간 차이와 성별 내 위치간 차이에 대해 측정 및 분석하였다. 남성과 여성에서 주름 빈도의 경우 손등과 아래팔 앞쪽은 여성이, 손가락은 남성이 통계적으로 유의하게 높았으며 동일 성별의 경우 남녀 모두 손가락의 경우에 주름의 빈도가 높게 나타남을 알 수 있었다. 상기 연구에 의한 결과는 건강한 젊은 남녀 한국인 피부 미세지형 자료로 추후 진행될 피부와 관련된 다양한 연구에 기초자료로 활용될 수 있으리라 생각된다.

• 대한소아치과학회지
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• 제34권1호
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• pp.106-121
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• 2007

본 연구는 치면열구전색술시 치과용 염료를 이용하여 초기 우식병소의 유무와 유기물의 잔재를 확인하고 산부식 액의 도포시 brushing방법을 이용하여 침투를 깊이 유도함으로써 열구내 법랑질의 산부식 상태를 유지력을 얻기 위한 최상의 상태로 만들고자 하는 목적으로 자연치를 대상으로 여러 가지 치면세마법과 비교하여 다음과 같은 결과를 얻었다. 1. 실험군은 기존의 치면세마법보다 변연누출이 적었으나 enameloplasty를 시행한 군과는 차이가 없었다. 2. 법랑질 산부식 형태의 질이 향상되었다. 3. 실험군은 다른 군에 비해 미세결합강도가 높았다. 4. 구강내 환경적 조건이 치면열구전색재의 성공실패를 좌우한다. 이상의 결과를 종합하면 치면열구전색술시 치과용 염료와 산부식 액의 도포시 brushing 방법을 이용하여 침투를 깊이 유도하므로써 수복물의 성공적인 도포를 제공할 수 있다고 사료된다.

• 대한치과보철학회지
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• 제39권5호
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• pp.526-546
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• 2001

Fiber-reinforced composite(FRC) was developed as a structural component for dental appliances such as prosthodontic framework. FRC provides the potential for fabrication of a metal-free, excellent esthetic prostheses. It has demonstrated success as a result of its simple fabrication, natural colour, and marginal integrity, and fracture resistance of veneering composite resin and the FRC material. Although it has lots of merits, clinical and objective data are insufficient. The purpose of this study was to evaluate the fracture strength and the marginal fitness of fiber reinforced composite bridge in the posterior region for clinical application. Sixteen bridges of each group. $Targis/Vectris^{(R)}$, $Sculpture-Fibrekor^{(R)}$, and In-Ceram, were fabricated. All specimens were cemented with Panavia 21 to the master dies. Strength evaluation was accomplished by a universal testing machine (Instron). The marginal fitness was measured by using the stereoscope (${\times}50$). The results were as follows. : 1. The fracture strength according to the materials was significantly decreased in order In-Ceram($238.81{\pm}82$), Targis Vectris($176.25{\pm}18.93$), Sculpture-Fibrekor($120.35{\pm}20.08$) bridges. 2. FRC resin bridges were not completely fractured, while In-Ceram bridges were completely fractured in the pontic joint. 3. The marginal accuracy was significantly decreased in order Targis/Vectris ($60.71{\mu}m$), Sculpture-Fibrekor($73.10{\mu}m$) In-ceram Bridge ($83.81{\mu}m$). 4. The fitness of occlusal sites had a lower value than the marginal sites(P<0.001), and the marginal gaps of inner site of the pontic were greater than that of outer sites of the pontic. Fiber reinforced composite bridges are new, esthetic prosthesis and can be clinically used in anterior regions and short span bridges. However, caution must be exercised when extrapolating laboratory data to the clinical situation because there are no long term clinical data regarding the overall success of the FRC.